Field Notes

Birdhouse Report for 2013

While visiting with family and friends on Thanksgiving Day, a lone female Bluebird was observed sitting high in the top of an apple tree. Had we searched the apples and shrubs further, we probably would have found others of her kind. Blues usually travel in family groups of four to 12 depending upon how successful they were at raising families last summer.

It occurred to me that this past nesting season has not been totaled and quantified, so this might be a good time to close the books on the Bluebirds. As disastrous as the 2012 nesting was, the summer of 2013 was just the opposite and a record number of Blues fledged into the real world.

Nineteen wooden birdhouses were observed every seven to 10 days by removing the tops and recording numbers of eggs or young inside. The Blues made 14 separate attempts and were successful in 12 of those nests for a success rate of 86 percent, which is much better than last year’s 18 percent. Also, 47 young fledged compared to only 13 in 2012 for an increase of 262 percent. It even bettered the 2010 season when 45 blues fledged.

The Tree Swallows also had a good year, being successful in 11 of 14 attempts and fledging 43 young birds. They produced 35 fledglings in 2012 in 16 nesting attempts.

House Wrens had three favorable nests and fledged 15 youngsters. There were probably more wren nests later in the season, but these were left ignored and uncounted. There is always an abundance of wrens and counting them is like counting clovers in a hayfield. You could do it, but why bother.

Overall it was a very successful season for the cavity nesters, but what would explain the huge differences between the two seasons?

First, there apparently wasn’t as much predation this year as last. In 2012 raccoons and other nest robbers played havoc on the bird boxes, stealing eggs and young in pursuit of a steady diet. In summer 2013, maybe the raccoon population had declined or alternative food sources were found.

Secondly, just a personal observation but Bluebirds often are timid parents and will shy away from their responsibility of protecting the nest. Not this year as every pair of parent birds seemed more determined than usual. These courageous little warriors were constantly flying in my face or within inches of my head while I was checking nests. Older birds are more likely to do that than first year parents.

Tree Swallows are always good parents. In fact a passing swallow will join in with others to help parent birds defend their lot and there may be five or six birds diving at your head. They do it just for fun.

Bobcat on the move

Rachel and Adam Taylor, of Arbovale, had an unusual visitor recently.

Last Monday Rachel heard a disturbance in the chicken house and looked out to see a bobcat walking around the lot, checking things out. She was able to record a pretty good video before running it off. Adam notes that no chickens were harmed during this close encounter.

The odd part is that the cat probably walked through neighbor Leon Nelson’s yard which always has tame rabbits running hither and yon. Apparently the cat couldn’t make up his mind between a rabbit or chicken dinner.

This is probably the same cat that Sandy Smith saw in our backyard a couple of months ago. Then it was in hot pursuit of a house cat which was headed home in a hurry.

There is a thick, cut-over pine patch in the neighborhood that would make excellent cover for most anything, and the presence of a bobcat may explain a couple of things. First the red fox that we used to see there hasn’t been seen in several months. It could be that old “dog and cat” thing. They just don’t get along.

Secondly, this same area usually has four-to-six adult deer and usually produces four-to-six fawns every year. This year only one fawn was seen. Now, bobcats don’t usually take fawns, but it can become a learned behavior in certain individual cats.

At any rate, the chickens, rabbits, fawns and house cats, that bobcat would be foolish to go anywhere else.

Just a suggestion

If you are still shopping for something for the budding naturalists on your list, I would recommend any of the Bernd Heinrich books like Summer World, Winter World or Mind of the Raven. Heinrich has written several books about his field research and they can be found at

They are written at an advanced high school level and are extremely readable and interesting – not filled with scientific jargon.

Dave is a telescope operator at the NRAO in Green Bank and can be contacted at


more recommended stories